My standard advice for people reading the books with the movies/mini-series mixed in:
Read the first one. It's not for everyone, it's a little dry, POV is all over the place, and it's very political and thoughtful. It can be a slow read, but it's worth it.
Watch the Lynch movie. (Lament that this could have been Alejandro Jodorowsky's Dune if so inclined.)
Watch the Sci-Fi Channel's Frank Herbert's Dune.
(Probably watch the Villeneuve Dune due out in December this year.)
If you happened to like it, read Dune Messiah and Children of Dune. You'll probably like these books as well. (If you didn't like Dune, it's okay to stop here.)
Watch the Sci-Fi Channel's Children of Dune.
If you happened to like those, try God Emperor of Dune. Be warned it is extremely different from the previous books. It's become my favorite book in the series after multiple re-readings of the entire series (previously was Dune Messiah), but it is certainly not for everyone. It's okay to quit here.
If you made it through God Emperor, read Heretics of Dune.
If you enjoyed it, read Chapterhouse: Dune. (If you didn't enjoy Heretics, don't bother).
Lament that it is over.
If you must, read Sandworms of Dune which is written by the son, but is supposedly based on the father's notes. It is the least bad of the books I've read by the son. Don't read anything else.
Definitely recommend the books (at least the ones written by the father, not the ones written by the son). The lynch movie departs quite a bit from the book, it's not a really bad movie per se but it's frustrating if you've read the books.
It has influenced a lot of games, books and movies so it's a classic well worth reading. The first third of the first book is a bit of a slog but it becomes very good after.
